“…However, some 60 per cent protrude in submucosa (Huddock, Wanner, and Reilly, 1956) and are nearly always sessile and oval. Kjellman (1950Kjellman ( , 1951 showed that they tend to have a central pseudo-crater into which their duct systems may open. In many no duct is discernible but a central dimple or umbilication still occurs and is covered by normal gastric mucosa (Benner,195 I).…”